If the Sky Comes Falling Down
by sk8r-grl
Summary: Set directly after the season 9 finale! Crowley is using his new-found Knight of Hell in order to fully reclaim his place as King of Hell. Castiel and Sam search for Dean before he is permanently changed by the darkness within him.
1. Aftershock

The black in Dean's eyes diminishes until only the pupils remain dark. He looks around him, lowering the First Blade and trying to catch his breath. He wonders what he's doing. How did he get _here_? He wipes a bloody hand off on his shirt absent-mindedly as the sound of slow clapping comes from behind him. Dean spins around, blade poised to slice.

"Woah, easy there, tiger," Crowley says calmly, hands raised and palms facing Dean. "Just came back to extend my thanks for ridding me of this lot."

Crowley lowers his arms, gesturing to the room behind Dean with a broad sweep of his right arm as he does so. Dean frowns and looks over his shoulder at the four demons that lay in bloody pieces on the floor of the run-down café. He grimaces as he recalls the bloodlust and enjoyment he got from slicing them to bits. From hearing their screams.

"Well," Crowley exhales, drawing Dean's attention back to him, "I have many King of Hell duties to attend to. I'll be in touch."

Crowley disappears before Dean's eyes and Dean is left in the room with the stomach-turning smell of blood mixed with sulfur, the sound of blood dripping off the First Blade, and the screaming of a single thought in his head: _How did he let himself get here?_

Castiel drives through the night, cutting off all communication with other angels, allowing himself to truly feel the loss of Dean. He cries out and slams his palms against the wheel of his crappy car, remembering how Dean would poke fun at the vehicle. He wipes his eyes roughly with the back of his hand and shrugs off his trench coat as the heater in the car makes it too warm. The loss of so much grace is not only killing him, it is making him more human. As the sun peeks over the horizon line, Castiel's car skids to a stop in front of the bunker. He knocks on the door loudly and repetitively. He needs to know if Metatron was lying. Metatron had to be lying. _Dean can't be—_

Sam opens the door and he's a mess. His hair is disheveled, his eyes are bloodshot and swollen and he reeks of whiskey. Not just any whiskey, but Dean's favorite whiskey.

– _Dead_.

Castiel murmurs, "No." And Sam's lower lips quivers before the younger Winchester sets his jaw and nods once. Sam catches Castiel as the angel topples forward, legs giving out beneath him as though the bones had been turned to noodles. Castiel allows Sam to assist him in walking and the Winchester practically drags Cas to a chair in the bunker's study. Castiel slumps in the chair, face a white sheet of shock. "I'm so sorry, Sam." He apologizes. "I should have destroyed the tablet faster. I should have looked for it harder. I am sorry, Sam."

Sam pats Castiel's shoulder before squeezing it, he shakes his head. "'s not your fault, Cas. It was Metatron…"

Castiel blinks away the tears pooling in his eyes. He takes a shaky breath before quietly inquiring, "Can I see him?"

"What?" Sam asks, leaning down to hear Castiel.

"Can… I need to see him, Sam." Castiel says a tad louder, keeping his eyes on where his hands rest in his lap.

"Yeah, uh, sure, Cas," Sam says in a small voice. He lets his hand fall from Castiel's shoulder.

Sam steps back and watches with concern as Castiel wobbles to his feet. Castiel feels nauseous as he follows Sam down the hallway. Towards Dean's room. Castiel messes with the hem of his suit jacket, missing the safety of his trench coat that still lies in the passenger seat of his car. They come to a stop a foot from Dean's doorway and Castiel sees Sam steeling himself for this. He lets his gaze flit to the ground, feeling for Sam's loss of a brother, friend, and childhood hero. Then, Sam's boots scuffle forwards only for the younger man to whisper, "What the hell?"

"What?" Castiel asks, voice tight with concern.

The angel joins Sam into peering into the bedroom and… it's empty. The bed is vacant save for a couple smears of blood in the middle. The smell of sulfur wafts into Castiel's nose at the same time Sam hisses, "Crowley."


	2. In the Details with the Devil

Dean sits on the front porch of the dilapidated house he killed the four demons in. The First Blade sits next to him as if it were his own shadow, unable to be separated from him. He wants desperately to be rid of it. He buries his face in his hands. Could he get back to the bunker from here? Where was here, exactly? He ponders praying to Cas, but the prayer sticks in the back of his throat. He doesn't want Cas to know. Not yet. Not ever, really. Dean can imagine the disappointment that will be on Castiel's face when he sees what Dean has become.

"Oh, man," Dean groans into his hands, wondering how this came to be…

_Dean felt different. And he knew he could hear Crowley's voice. He knew he felt dead. He'd felt dead for a while. But now… It was different. And he was scared to follow Crowley's commands to "open his eyes" and "see how he sees" because that could only mean one thing. Dean listened as Crowley finished his monologue with, "Let's go take a howl at that moon."_

_ Dean opened his eyes. And everything seemed different although it was the same. He looked over at Crowley and the king of Hell had a smile as wickedly wide as the Cheshire cat's. Dean lifted his empty hand to the puncture wound in his chest. It was still there, a gaping hole inside him. But it wasn't bleeding. And he wasn't dead. How was he not dead? Dean gapes over at Crowley before frowning and rising to his feet. Crowley's story couldn't be true…_

_ He couldn't be a…_

_ "What…" Dean stopped, licking his lips. "What am I?"_

_ Crowley smirked, wandering away from the bed as Dean pushed himself to a seat. "Well, my dear," he droned as he fiddled with the mirror that hung on Dean's wall. He removes it before turning back to Dean, "it just so happens that you have crossed over to, shall we say, the dark side." Crowley lifted the small mirror to face Dean and Dean saw himself. Saw his punctured chest, blood-stained shirt, his washed face, and his eyes._

_ Oh, his _eyes.

_ Dean jumped back. They were black. Pitch black. He went to look at them again, but they had gone back to their usual shade of green, if not slightly duller. He felt his chest constricting along with his throat. He can't be this. He wiped a hand down his face before assessing Crowley. "What… So, I'm a..?"_

_ "A demon? Yes and no." Crowley said cryptically, leaning back against Dean's dresser._

_ "The hell does that mean?"_

_ "Well, you are a demon, but you are so much more than that, sweet-cheeks." Crowley replied, looking Dean up and down once. "You're a Knight of Hell. My Knight of Hell, actually."_

_ Dean scoffed. "Like hell I'm gonna work for you."_

_ "Dean," Crowley sighed ,cupping his chin while resting is elbow upon his other forearm, "it's not exactly like you can go back to the bunker all sunshine and rainbows. What'll Moose do when he sees what you are? What you've become? His job is to hunt our kind. I know, I know; this is a bit of a grey area. But Sam won't hesitate if he sees your little party trick." Crowley motions a hand in front of his eyes, causing them to momentarily turn black before he blinks them back to normal, "Now, will he?"_

_ Dean clenched his jaw, remembering the time Sam was drinking demon blood and Dean had told his brother that "if he hadn't known him, he would want to hunt him" and how the roles here were reversed. And in this case, Dean actually was a monster._

_ Crowley continued, "And it's not like the fading angel is gonna want to cohabitate with his arch enemies."_

_ "We don't '_cohabitate_,'" Dean sneered, using his anger to mask the hurt that he felt in his still heart._

_ "No, but you wanted to, eh?" Crowley smirked, looking like a pesky pre-teen who had found their big sister's diary._

_ If Dean could still blush, he would have in that moment as he looked away from the king of Hell, mouth snapping shut quickly. Crowley's low chuckle irritated Dean and he pretended he didn't hear it. "Anyway," Crowley continued as he strode over to stand before Dean, "I probably understand what you're feeling better than those two yahoos. You still wanna kill, right?"_

_ Dean looked up at Crowley with a dark frown._

_ "I'll take that as a 'yes.' I can get you things to kill. I can satisfy that sweet tooth of yours, Dean." Crowley purred. "And, the best part is, they'll be demons you'll be killing."_

_ Dean furrowed his brow. "What do you mean?"_

_ "Just loose ends that need to be dealt with. Followers of Abaddon. People who break their contracts." Crowley listed off, waving his hand in the air. "So, you'll still be hunting, per se."_

_ Dean nodded once._

_ "So, do we have an understanding?" Crowley asked, sticking out a hand towards the hunter._

Dean pulls his hands down his face before letting them fall to his lap where his left hand worries his right forearm where the Mark resides. He wonders if Sam _will_ try to exorcise him should he return. He wonders if Cas will use the rest of his grace to light him up like a firework. He knows he deserves it. After all, he's a demon. He wishes either of those would be enough, but he's Cain now. And he can't die. Well, not in any way he knows of.

Dean stands up after a few moments of pondering. He knows he has to get back to the bunker. Sam may consider helping him; Sam is smart and Dean hopes that Sam will take the fact that they are family into account. Dean looks at the Blade and thinks about leaving it behind. His fingers twitch and he grasps the handle before sliding the weapon under his blood-stained plaid shirt. Dean frowns; Crowley could have at least given him a different shirt than the one he died in.

He sighs and finally rises to his feet. Looking West, Dean heads towards the lights of the town down the hill that glow in the fading daylight.


	3. The Prodigal Son

"What do you_ mean _yousummoned_ Crowley_?" Castiel's voice is tight as though he is holding himself back from strangling Sam.

"It means I friggin' summoned him!" Sam exhales, running a hand through his hair, pacing through Dean's vacant room again. "I wasn't gonna… Cas, I wasn't going to make a deal."

Castiel shoots the younger Winchester a disbelieving look from under furrowed eyebrows.

"I wasn't!" Sam defends himself. "I was going to see if he could do anything about the damn Mark of Cain and…. Yes, ok, I was going to get him to bring Dean back, but not by trading my soul!"

"Well, this changes nothing," Castiel finally grumbles. "Dean is still gone. Who knows if he's being used as a demon's vessel or… worse…" Castiel's tone changes at the last part of the statement. The agony in his tone causes Sam's head to snap up.

"Worse?"

Castiel purses his lips, looking at the doorframe. "Dean bore the Mark of Cain—the mark of murder and evil. I fear that the Mark could cause his soul to be claimed by Hell once more regardless of how inherently good Dean actually is."

"What?" Sam feels as though he was punched right in the gut.

Cas looks down and away, feeling the sickness churning deep in his stomach. He also feels as though his heart is being squeezed and it's an unfamiliar ache that causes the angel distress and worry. He sits down, bowing his head and breathing in deeply, trying to steady the frantic beating and stop the building tears and regain composure because Sam did not need him breaking down. Hell, the boy already looked as though his heart had been ripped from his chest.

"B-but Crowley never showed." Sam weakly offers.

"What?" Castiel asks, looking up with a tilt of his head.

"Yeah, I, uh, I did the ritual and Crowley never showed." Sam explains, pushing his hair away from his face.

Castiel squints at Sam, the wheels in his head grinding as he tries to figure out how this could be. "But if you summoned him correctly, he would have to show up…" Castiel murmurs. "But maybe…"

"What?" Sam exclaims, peering at Castiel.

"Perhaps Crowley did appear when you summoned him, just not where you were."

"So, he came into the bunker, took Dean's body, and…" Sam ponders, a look of dread consuming his features, he straightens and starts for his supplies. "We need to summon Crowley."

"No." Castiel stands and stops Sam with a hand on his arm. "If Crowley knows we have this knowledge, he'll make sure we never find Dean's body. Or worse.

"We should research this. See who Crowley's second-in-command would be. It's likely that, if Crowley did have Dean's body possessed, it would be by his most loyal follower." Castiel reasons.

Sam purses his lips and nods. They two head into the Men of Letters' extensive library. Sam pulls out every book on Hell he can find while Castiel gathers documents of exorcisms closely related to demons of crossroads. They sit opposite each other at one of the long tables, spread out their reading material and get to work. Castiel glances up at the clock; it reads ten o'clock at night. He already feels tired even though the remainder of his stolen grace is fighting to keep him somewhat an angel. He sets his gaze back to the handwritten documents before him and reads every word with intense focus.

Dean wanders through the town. He finds out that the place Crowley had dragged him is only a mile outside of Lebanon, Kansas. Unfortunately, the bunker is on the opposite side of the town and he is wary as he wanders through the town at dusk. He keeps the Blade tucked under his blood-stained plaid over shirt. There are few people on the street and Dean is grateful that he goes mostly unnoticed. One lovely young blonde gives him a horrified look and walks rapidly past him. He frowns, folding his arms in front of the hole in his chest. As the sun finally disappears, so do all the people and Dean walks through neighborhoods undisturbed. He wonders if he'll be able to enter the bunker due to the warding or if his Cain-like status will render the devil's traps useless just like how Cain had been unaffected by the demon blade.

Dean passes the last trailer home in the town and wanders off the road and into the woods that hide the bunker from civilization. He treks uphill for an hour and a half, winding through the shrubbery. Finally, the trail to the bunker comes into view and he breathes a sigh of relief. He is almost home. As he grows closer to the bunker, his nerves increase. He considers turning around and leaving, but… He cannot bring himself to do it. He needs to research. He needs to know how to kill the ultimate Knight of Hell—himself.

Dean comes to a stop at the door of the bunker, knowing that the cement used to build the place was laced with salt and mixed in holy water. He slowly, cautiously touches the door and feels nothing but a slight tingle as if his hand has fallen asleep. He pats his pockets, realizing he doesn't have a key to the underground building. He purses his lips, raises a closed fist, and knocks on the concrete door.

Castiel groggily awakes to a pounding. He lifts his head up from the table where he had, apparently, fallen asleep. Sam is giving him a look of concern before he picks up a gun. "Someone's here." The Winchester whispers tensely, standing. Castiel stands abruptly, his chair scraping the floor slightly as he draws his angel blade. The two walk slowly, quietly to the door of the bunker. Someone is knocking. Sam is ready for a fight, his gun raised and aimed at the door as he reaches for the knob. Castiel crouches like a puma ready to pounce as Sam twists the knob

In one swift motion, Sam yanks the door open, aims his gun and Castiel flips his blade in his hand, ready for a battle.

"I, uh, I guess I forgot my key to the place…" Dean's voice is gruff and deep as he looks at the two men poised to attack from under his blonde eyelashes.


End file.
